Expectancies
Only behaviours that disconfirm expectancies are truly informative about an actor. There are two types of expectancy. Category-based expectancies are those derived from our knowledge about particular types or groups of people. For example, if you were surprised to hear a wealthy businessman extolling the virtues of socialism, your surprise would rest on the expectation that businessmen (a category of people) are not usually socialist.
Target-based expectancies derive from knowledge about a particular person. To know that a person is a supporter of Margaret Thatcher sets up certain expectations and associations about their beliefs and character.
Read more about this topic: Correspondent Inference Theory